What is "Quantumstuff"?

[Dr Alain L Fymat]

Classical physics accounts for the world by means of two real physical entities - matter and force fields, and we know the laws of both entities - Newton’s motion laws and Maxwell’s field laws.

Newton’s laws are deterministic: second by second the universe, like a giant clockwork, ticks out, its future as fixed and immutable as its past. Maxwell’s field laws of electricity and magnetism point to light as a wave motion in the electromagnetic field. However, these two sets of laws could not both be reconciled with the newly observed fact that despite the Earth’s motion the velocity of light was constant in all directions. Something in classical physics had to give. Einstein kept Maxwell’s laws intact but replaced Newton’s laws with his own relativistic laws of motion. These new laws make light’s speed a constant for all observers. Maxwell’s laws plus the relativistic laws of motion now completely and consistently describe all classical motion even at high velocity. Einstein’s attitude toward reality is no different from Newton’s. These are real fields here, real matter we are dealing with. Special relativity caused no reality crisis in physics.

However, three experiments made a revolution in this picture: the blackbody radiation, the photoelectric absorption effect, and the Compton scattering effect. They all indicated that light consists of particles, which conflicts with numerous 19^th-century optical experiments in which light acts as a wave.

The puzzle of the blackbody radiation (it does not obey Newton’s law) was to explain why do hot objects glow red whereas physicists kept coming with the same answer that blackbodies glow bright blue at all temperatures. Planck’s energy law is the answer: E = hf, where E is the particle’s energy, f is the particle vibration frequency, and h is Planck’s constant (also called “quantum of action”). When h = 0, it explains the blue glow; however, when h is set to one particular value, it matches the experiment exactly. Light is caused by moving electrons; however, not only do electrons not follow classical laws, they do not even follow a classical kind of law.

Using h, Einstein explained how light interacts with electrons in a metal (called “photoelectric effect”). Here, upon interaction, one photon goes in, but none comes out. His analysis demonstrated the non-classical nature of light so unmistakably that physicists could no longer ignore the mysterious quantum. This paper swept physicists headlong into the Quantum Era.

In turn, Compton explained how light interacts with electrons in a gas (called “Compton scattering effect”). Here, upon interaction, one recoil photon and one ejected electron are observed. The experiment showed that light behaves precisely like a little particle bouncing off the electron, provided this light is assigned a momentum p according to the quantum rule: p = hk, where k is the light’s spatial frequency.

In addition and conversely, de Broglie demonstrated that matter would show wave properties, an important step in the understanding of quantum reality. With two magic phrases, we can translate at will between the particle quantities energy (E) and momentum (p) and the wave quantities temporal (f) and spatial (k) frequencies, turning matter into field and vice versa..

In summary, whereas classical physics built its world out of two kinds of entities, matter and filed (also known as particle and waves), Planck, Einstein, and Compton showed that waves (at least light waves) were also particles. Further, de Broglie showed that particles are also waves. These new quantum facts destroyed the once sharp distinction between matter and field. By dissolving the matter/field distinction, quantum physicists realized a dream of the ancient Greeks who speculated that beneath its varied appearances the world was ultimately composed of a single substance. Herbert calls it “quantumstuff”. However, we do not understand the nature of that substance. For if quantumstuff is all there is and we don’t understand quantumstuff, our ignorance is complete. Do you understand what is this quantumstuff?

Lastly, Einstein changed our ordinary ideas of time and space, notions that seemed so deeply embedded in human experience as to be unquestionable. In his new vision, measurements of length and time are not absolute but depend on the observer’s velocity. He also elevated the speed of light to a universal speed limit which no signal can exceed. Einstein’s special theory of relativity had profound consequences for physics and philosophy, for it showed that some of our most cherished notions about the world are simply wrong and must be replaced with entirely new ways of thinking.